In the context of a steam turbine plant, a diversion station serves the purpose, as bypass, of feeding the water vapor formed in a steam generator directly to a condenser past a (steam) turbine. Such a bypass is required, for example, when the running times of steam generator and turbine are not mutually synchronized. By way of example, as early as before the start up of the turbine or still during the shutdown of the turbine, water vapor is generated that cannot be used by the turbine in these operating states.
In order not to damage the condenser when introducing the “unused” water vapor, as a rule in the diversion station the steam pressure is throttled, on the one hand, and the water vapor is cooled by injection of water, on the other hand. The water injected into the water vapor is heated and evaporated, the water vapor conversely being cooled.
In what follows here the term “water” always denotes water in its liquid aggregate state, particularly in drop form, while the term “water vapor” denotes water in its gaseous aggregate state.
The water is frequently injected through a plurality of nozzle stocks aligned transverse to the flow direction and mixed with the water vapor. In an alternative to this, the water is injected into the water vapor in a (single) jet, the mixing usually being implemented by an orifice. It is disadvantageous that comparatively large mixing lengths are required in both variants for mixing—and therefore for successful cooling. In addition, mixing orifices used are subject to relatively high wear from so-called drop impact.